<?php
namespace App\Baqi\Wxpay;

    /**
     * 微信支付服务器端下单
     * 微信APP支付文档地址:  https://pay.weixin.qq.com/wiki/doc/api/app.php?chapter=8_6
     * 使用示例
     *  构造方法参数
     *      'appid'     =>  //填写微信分配的公众账号ID
     *      'mch_id'    =>  //填写微信支付分配的商户号
     *      'notify_url'=>  //填写微信支付结果回调地址
     *      'key'       =>  //填写微信商户支付密钥
     *  );
     *  统一下单方法
     *  $WechatAppPay = new wechatAppPay($options);
     *  $params['body'] = '商品描述';                   //商品描述
     *  $params['out_trade_no'] = '1217752501201407';   //自定义的订单号，不能重复
     *  $params['total_fee'] = '100';                   //订单金额 只能为整数 单位为分
     *  $params['trade_type'] = 'APP';                  //交易类型 JSAPI | NATIVE |APP | WAP 
     *  $wechatAppPay->unifiedOrder( $params );
     */
    class WechatAppPay
    {   
        //接口API URL前缀
        const API_URL_PREFIX = 'https://api.mch.weixin.qq.com';
        //下单地址URL
        const UNIFIEDORDER_URL = "/pay/unifiedorder";
        //查询订单URL
        const ORDERQUERY_URL = "/pay/orderquery";
        //关闭订单URL
        const CLOSEORDER_URL = "/pay/closeorder";
        //公众账号ID
        private $appid;
        //商户号
        private $mch_id;
        //随机字符串
        private $nonce_str;
        //签名
        private $sign;
        //商品描述
        private $body;
        //商户订单号
        private $out_trade_no;
        //支付总金额
        private $total_fee;
        //终端IP
        private $spbill_create_ip;
        //支付结果回调通知地址
        private $notify_url;
        //交易类型
        private $trade_type;
        //支付密钥
        private $key;
        //证书路径
        private $SSLCERT_PATH;
        private $SSLKEY_PATH;
        //所有参数
        private $params = array();
        public function __construct($appid, $mch_id, $notify_url, $key)
        {
            $this->appid = $appid;
            $this->mch_id = $mch_id;
            $this->notify_url = $notify_url;
            $this->key = $key;
        }
        /**
         * 下单方法
         * @param   $params 下单参数
         */
        public function unifiedOrder( $params ){
            $this->body = $params['body'];
            $this->out_trade_no = $params['out_trade_no'];
            $this->total_fee = $params['total_fee'];
            $this->trade_type = $params['trade_type'];
            $this->nonce_str = $this->genRandomString();
            $this->spbill_create_ip = $_SERVER['REMOTE_ADDR'];
            $this->params['appid'] = $this->appid;
            $this->params['mch_id'] = $this->mch_id;
            $this->params['nonce_str'] = $this->nonce_str;
            $this->params['body'] = $this->body;
            $this->params['out_trade_no'] = $this->out_trade_no;
            $this->params['total_fee'] = $this->total_fee;
            $this->params['spbill_create_ip'] = $this->spbill_create_ip;
            $this->params['notify_url'] = $this->notify_url;
            $this->params['trade_type'] = $this->trade_type;
            //获取签名数据
            $this->sign = $this->MakeSign( $this->params );
            $this->params['sign'] = $this->sign;
            $xml = $this->data_to_xml($this->params);
            $response = $this->postXmlCurl($xml, self::API_URL_PREFIX.self::UNIFIEDORDER_URL);
            if( !$response ){
                return false;
            }
            $result = $this->xml_to_data( $response );
            if( !empty($result['result_code']) && !empty($result['err_code']) ){
                $result['err_msg'] = $this->error_code( $result['err_code'] );
            }
            return $result;
        }
        /**
         * 查询订单信息
         * @param $out_trade_no     订单号
         * @return array
         */
        public function orderQuery( $transaction_id ){
            $this->params['appid'] = $this->appid;
            $this->params['mch_id'] = $this->mch_id;
            $this->params['nonce_str'] = $this->genRandomString();
            $this->params['transaction_id'] = $transaction_id;
            //获取签名数据
            $this->sign = $this->MakeSign( $this->params );
            $this->params['sign'] = $this->sign;
            $xml = $this->data_to_xml($this->params);
            $response = $this->postXmlCurl($xml, self::API_URL_PREFIX.self::ORDERQUERY_URL);
            if( !$response ){
                return false;
            }
            $result = $this->xml_to_data( $response );
            return $result;
            if( !empty($result['result_code']) && !empty($result['err_code']) ){
                $result['err_msg'] = $this->error_code( $result['err_code'] );
            }
            return $result;
        }
        /**
         * 关闭订单
         * @param $out_trade_no     订单号
         * @return array
         */
        public function closeOrder( $out_trade_no ){
            $this->params['appid'] = $this->appid;
            $this->params['mch_id'] = $this->mch_id;
            $this->params['nonce_str'] = $this->genRandomString();
            $this->params['out_trade_no'] = $out_trade_no;
            //获取签名数据
            $this->sign = $this->MakeSign( $this->params );
            $this->params['sign'] = $this->sign;
            $xml = $this->data_to_xml($this->params);
            $response = $this->postXmlCurl($xml, self::API_URL_PREFIX.self::CLOSEORDER_URL);
            if( !$response ){
                return false;
            }
            $result = $this->xml_to_data( $response );
            return $result;
        }
        /**
         * 
         * 获取支付结果通知数据
         * return array
         */
        public function getNotifyData(){
            //获取通知的数据
            $xml = $GLOBALS['HTTP_RAW_POST_DATA'];
            $data = array();
            if( empty($xml) ){
                return false;
            }
            $data = $this->xml_to_data( $xml );
            if( !empty($data['return_code']) ){
                if( $data['return_code'] == 'FAIL' ){
                    return false;
                }
            }
            return $data;
        }
        /**
         * 接收通知成功后应答输出XML数据
         * @param string $xml
         */
        public function replyNotify(){
            $data['return_code'] = 'SUCCESS';
            $data['return_msg'] = 'OK';
            $xml = $this->data_to_xml( $data );
            echo $xml;
            die();
        }
         /**
          * 生成APP端支付参数
          * @param  $prepayid   预支付id
          */
         public function getAppPayParams( $prepayid ){
             $data['appid'] = $this->appid;
             $data['partnerid'] = $this->mch_id;
             $data['prepayid'] = $prepayid;
             $data['package'] = 'Sign=WXPay';
             $data['noncestr'] = $this->genRandomString();
             $data['timestamp'] = time();
             $data['sign'] = $this->MakeSign( $data ); 
             return $data;
         }
        /**
         * 生成签名
         *  @return 签名
         */
        public function MakeSign( $params ){
            //签名步骤一：按字典序排序数组参数
            ksort($params);
            $string = $this->ToUrlParams($params);
            //签名步骤二：在string后加入KEY
            $string = $string . "&key=".$this->key;
            //签名步骤三：MD5加密
            $string = md5($string);
            //签名步骤四：所有字符转为大写
            $result = strtoupper($string);
            return $result;
        }
        /**
         * 将参数拼接为url: key=value&key=value
         * @param   $params
         * @return  string
         */
        public function ToUrlParams( $params ){
            $string = '';
            if( !empty($params) ){
                $array = array();
                foreach( $params as $key => $value ){
                    $array[] = $key.'='.$value;
                }
                $string = implode("&",$array);
            }
            return $string;
        }
        /**
         * 输出xml字符
         * @param   $params     参数名称
         * return   string      返回组装的xml
         **/
        public function data_to_xml( $params ){
            if(!is_array($params)|| count($params) <= 0)
            {
                return false;
            }
            $xml = "<xml>";
            foreach ($params as $key=>$val)
            {
                if (is_numeric($val)){
                    $xml.="<".$key.">".$val."</".$key.">";
                }else{
                    $xml.="<".$key."><![CDATA[".$val."]]></".$key.">";
                }
            }
            $xml.="</xml>";
            return $xml; 
        }
        /**
         * 将xml转为array
         * @param string $xml
         * return array
         */
        public function xml_to_data($xml){  
            if(!$xml){
                return false;
            }
            //将XML转为array
            //禁止引用外部xml实体
            libxml_disable_entity_loader(true);
            $data = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);        
            return $data;
        }
        /**
         * 获取毫秒级别的时间戳
         */
        private static function getMillisecond(){
            //获取毫秒的时间戳
            $time = explode ( " ", microtime () );
            $time = $time[1] . ($time[0] * 1000);
            $time2 = explode( ".", $time );
            $time = $time2[0];
            return $time;
        }
        /**
         * 产生一个指定长度的随机字符串,并返回给用户 
         * @param type $len 产生字符串的长度
         * @return string 随机字符串
         */
        private function genRandomString($len = 32) {
            $chars = array(
                "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k",
                "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
                "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G",
                "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R",
                "S", "T", "U", "V", "W", "X", "Y", "Z", "0", "1", "2",
                "3", "4", "5", "6", "7", "8", "9"
            );
            $charsLen = count($chars) - 1;
            // 将数组打乱 
            shuffle($chars);
            $output = "";
            for ($i = 0; $i < $len; $i++) {
                $output .= $chars[mt_rand(0, $charsLen)];
            }
            return $output;
        }
        /**
         * 以post方式提交xml到对应的接口url
         * 
         * @param string $xml  需要post的xml数据
         * @param string $url  url
         * @param bool $useCert 是否需要证书，默认不需要
         * @param int $second   url执行超时时间，默认30s
         * @throws WxPayException
         */
        private function postXmlCurl($xml, $url, $useCert = false, $second = 30){       
            $ch = curl_init();
            //设置超时
            curl_setopt($ch, CURLOPT_TIMEOUT, $second);
            curl_setopt($ch,CURLOPT_URL, $url);
            curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);
            curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,2);
            //设置header
            curl_setopt($ch, CURLOPT_HEADER, FALSE);
            //要求结果为字符串且输出到屏幕上
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
            if($useCert == true){
                //设置证书
                //使用证书：cert 与 key 分别属于两个.pem文件
                curl_setopt($ch,CURLOPT_SSLCERTTYPE,'PEM');
                //curl_setopt($ch,CURLOPT_SSLCERT, WxPayConfig::SSLCERT_PATH);
                curl_setopt($ch,CURLOPT_SSLKEYTYPE,'PEM');
                //curl_setopt($ch,CURLOPT_SSLKEY, WxPayConfig::SSLKEY_PATH);
            }
            //post提交方式
            curl_setopt($ch, CURLOPT_POST, TRUE);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
            //运行curl
            $data = curl_exec($ch);
            //返回结果
            if($data){
                curl_close($ch);
                return $data;
            } else { 
                $error = curl_errno($ch);
                curl_close($ch);
                return false;
            }
        }
        /**
          * 错误代码
          * @param  $code       服务器输出的错误代码
          * return string
          */
         public function error_code( $code ){
             $errList = array(
                'NOAUTH'                =>  '商户未开通此接口权限',
                'NOTENOUGH'             =>  '用户帐号余额不足',
                'ORDERNOTEXIST'         =>  '订单号不存在',
                'ORDERPAID'             =>  '商户订单已支付，无需重复操作',
                'ORDERCLOSED'           =>  '当前订单已关闭，无法支付',
                'SYSTEMERROR'           =>  '系统错误!系统超时',
                'APPID_NOT_EXIST'       =>  '参数中缺少APPID',
                'MCHID_NOT_EXIST'       =>  '参数中缺少MCHID',
                'APPID_MCHID_NOT_MATCH' =>  'appid和mch_id不匹配',
                'LACK_PARAMS'           =>  '缺少必要的请求参数',
                'OUT_TRADE_NO_USED'     =>  '同一笔交易不能多次提交',
                'SIGNERROR'             =>  '参数签名结果不正确',
                'XML_FORMAT_ERROR'      =>  'XML格式错误',
                'REQUIRE_POST_METHOD'   =>  '未使用post传递参数 ',
                'POST_DATA_EMPTY'       =>  'post数据不能为空',
                'NOT_UTF8'              =>  '未使用指定编码格式',
             ); 
             if( array_key_exists( $code , $errList ) ){
                return $errList[$code];
             }
         }
    } 